which Sfena is responsible is the central
ised fault display interface unit, which
monitors the aircraft's 80 avionic systems.
Although it is primarily a maintenance
tool, this unit does ease the pilot's
monitoring task, and is activated using
one of the two multifunction control
display units.
If the aircraft is on the ground, the fault
is displayed to the technician using the
system. In flight, the fault is radioed
directly back to base, using an Acars/
Aircom-type airliner datalink.
Under the prime contractorship of
Cerberus-Guinard, Sfena also manu
factures the A320 smoke detection control
unit. This receives signals from the vari
ous smoke detectors and triggers a warn
ing. Other safety-related A320 equipment
produced by Sfena includes the wing
strain gauges, used to warn pilots of exces
sive gloads.
Sfena intends to compete with Honey
well for the A320's air data/inertial refer
ence system. The US company has already
been selected, but Sfena is striving for
certification of its rival system. An
important stage has been reached with the
acceptance of its Totem 100 laser-gyro
inertial system, designed for future
military aircraft. This is now undergoing
flight trails on various aircraft.
In support of the A320 programme,
Sfena has introduced software devel
opment facilities which, it says, reduce
production time, increase validation
safety, and enhance maintenance effi
ciency. Principal examples are the Palas
configuration control programme to aid
software development and management,
Overall, Sfena's commercial aviation
activities during 1986 increased from 28
per cent to almost 35 per cent of total
turnover.
Preparation for the Airbus A330 and
A340 programmes is already under way. In
particular, Sfena hopes to supply the
A330/A340 cockpit displays, and is
moving rapidly ahead with full-raster
"all-TV" displays providing "richer
images" than the mixed stroke-
written/raster-scanned displays used in
the A320. Also under development are
liquid-crystal displays. The A330/A340
cockpit is likely to have five large displays
arranged side by side, says Sfena.
All this electronic hardware does not
mean that Sfena has departed entirely
from its traditional areas of expertise,
however. The gyroscopic artificial horizon
which made the company famous is still
available, and still required, even in the
all-glass cockpit, Sfena notes.
The company is also producing auto
matic flight control systems for helicop
ters and automatic guidance systems for
Clockwise from bottom right the spoiler and elevator computer, a close-up of the EPROMs on a
plug-in memory module, the inside of the spoiler and elevator computers, and an internal view of the
flight augmentation computer—all parts of the Airbus A320 fly-by-wire sytem
and the Gala system for automatic code
management according to control laws
expressed in graphic form. This allows
faster debugging and reduces the risk of
errors, says Sfena.
The first fully fly-by-wire airliner, the
A3 20 has two main actuators per control
surface, compared with three on current
Airbuses, but offers the same safety level.
This and other simplifications reduce the
number of flight control system units to
ten in the A320, compared with 48 in the
A310. System cost decreases from around
$300,000 in the bigger Airbuses to about
$190,000 in the A320, says Sfena.
The company, which is 51 per cent
owned by Aerospatiale, has fully recovered'
from its order slump during the airliner-
buying recession which bottomed out in
1984. Sfena's turnover in 1986 showed a
considerable improvement over the
previous year—almost FFr940 million
against some FFr810 million in 1985—an
increase of 21 per cent.
Commerical aviation sales accounted
for a significant proportion of this growth:
sales were up 38 per cent to almost FFr485
million. This is mainly attributable to
Airbus sales of FFr403 million, represent
ing an increase of almost 45 per cent over
the previous year.
missiles, and claims to have pioneered full
digital control with high-integrity soft
ware.
Other business areas include automatic
gunfire scoring systems, rate and acceler
ation sensors, electrical actuators for
helicopters and missiles, and lasers for
industrial and airborne applications. S3
Laser tests airspeed
Crouzet has developed a laser
anemometerrfor flight tests. An accu
racy of 0 • 5kt up to 840kt and 50,000ft
is claimed. Flight tests were carried out
on a Mirage IIIR from April to
September 1987.
The operating principle involves
transmitting a coherent laser beam of
10-6 micron wavelength through the
atmosphere and measuring the
Doppler effect on the light back-
scattered from particles in the air. The
laser meassures airspeed outside the
distrubed flowfield.
This equipment is designed to be
used in flight-test centres for cali
bration purposes and for all tests
requiring accurate knowledge of the
airspeed vector.
FLIGHT INTERNATIONAL, 13 February 1988 •in